One of the plots in the datasheet shows Mute attenuation vs Mute pin voltage. Those conditions show <~1.4V as full mute disable. Best to stay out of gray undefined logic areas and attempt to get as close to 0V and 5V as practically feasible.

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It is error only, and not truth, that shrinks from enquiry. - Thomas Paine

I kept circuit as it is for half an hour. And power on again. This time amp was mute and could not play. Power switch OFF and ON immediately, Amp started playing after 2-3 Seconds. I could not understand, why amp could not played first time ?

There is no problem in mute circuit... Overall something is wrong with my Amp or power supply. I disconnected mute and played as it was basic build. I found, 1st time it does not played. Switch off and immediately switch on and played. Just playing half an hour, then switch OFF and immediately switch on not played again..

It is working like toggle switch NOT PLAYED = SWITCH OFF- AND SWITCH ON = PLAYED..

why ? I found, SWITCH-ON = NOT PLAYED. condition .... I measure the voltage at power supply. 22(+/-)VDC correctly supplied to Power-amp but Regulator 7818 is not supplying +18VDC DMM shows below <1 vdc WHY ? I could not understand.

Again SWITCH-OFF AND SWITCH-ON condition Amp stared playing and Regulator 7818 correctly shows +18VDC by DMM.

I think you cannot power up simultaneously the crossover and the amp
A crossover produces a big thump at powering on and off, so it's preferable to power both on and off in the right sequence.
I am not shure you can manage this using mute only.